Iver Sims was trapped on top of a swaying, 75-metre (250-foot) crane above a raging warehouse fire in East Atlanta for more than an hour.
He was forced to escape from his cabin after it was engulfed by flames stretching high into the sky.
After crawling to the concrete counter-weight at the end of the crane’s horizontal arm to get away from the black smoke and flames, he lay on his stomach, waiting to be rescued.
Mr Mosley says flames were licking at the cable as he climbed onto the crane and scrambled to Ivers Sims clinging on the end.
He strapped the worker into a harness and held on tightly as both were lowered by the helicopter to the grass nearby.
Mr Sims, from Woodland, Alabama, was applauded by spectators as he walked to a stretcher before being wheeled to an ambulance.
He was treated for smoke inhalation and heat exposure, and remained overnight in hospital where he was “still overwhelmed”, according to a hospital spokeswoman.
Mr Mosley said he tried to joke with Mr Sims because the flames were so hot.
“That helped lighten things up a little bit. He was pretty much calm.”
The firefighter said that as he dangled above the warehouse inferno, he was thinking “I hope the rope doesn’t break.”
The fire engulfed an old five-storey mill that was being converted to loft apartments and spread to at least another two houses.
Larry Rogers, who was in the helicopter to guide the pilot and the cable, described the intense heat 25 metres (80 feet) above the cable.
“I had to put my visor down,” he said. “The heat was pretty tough.”
“People say, ‘You seem to be really calm,’ but when you’ve been training for this, you just do it – it’s your job,” the former army pilot said.
“I used to pluck Special Forces teams out of Laos and Cambodia.”